Vitamin E Acetate in Bronchoalveolar-Lavage Fluid Associated with EVALI.

BACKGROUND: The causative agents for the current national outbreak of electronic-cigarette, or vaping, product use-associated lung injury (EVALI) have not been established. Detection of toxicants in bronchoalveolar-lavage (BAL) fluid from patients with EVALI can provide direct information on exposure within the lung. METHODS: BAL fluids were collected from 51 patients with EVALI in 16 states and from 99 healthy participants who were part of an ongoing study of smoking involving nonsmokers, exclusive users of e-cigarettes or vaping products, and exclusive cigarette smokers that was initiated in 2015. Using the BAL fluid, we performed isotope dilution mass spectrometry to measure several priority toxicants: vitamin E acetate, plant oils, medium-chain triglyceride oil, coconut oil, petroleum distillates, and diluent terpenes. RESULTS: State and local health departments assigned EVALI case status as confirmed for 25 patients and as probable for 26 patients. Vitamin E acetate was identified in BAL fluid obtained from 48 of 51 case patients (94%) in 16 states but not in such fluid obtained from the healthy comparator group. No other priority toxicants were found in BAL fluid from the case patients or the comparator group, except for coconut oil and limonene, which were found in 1 patient each. Among the case patients for whom laboratory or epidemiologic data were available, 47 of 50 (94%) had detectable tetrahydrocannabinol (THC) or its metabolites in BAL fluid or had reported vaping THC products in the 90 days before the onset of illness. Nicotine or its metabolites were detected in 30 of 47 of the case patients (64%). CONCLUSIONS: Vitamin E acetate was associated with EVALI in a convenience sample of 51 patients in 16 states across the United States. (Funded by the National Cancer Institute and others.).

Optimal Cutoff Concentration of Urinary Cyanoethyl Mercapturic Acid for Differentiating Cigarette Smokers From Nonsmokers.

INTRODUCTION: Cotinine is a widely used biomarker for classifying cigarette smoking status. However, cotinine does not differentiate between the use of combustible and noncombustible tobacco products. The increasing use of noncombustible tobacco drives the need for a complementary biomarker for distinguishing cigarette smokers from users of noncombustible tobacco products. AIMS AND METHODS: We evaluated the urinary acrylonitrile metabolite, 2CyEMA, as a biomarker of exposure to cigarette smoke in the US population-representative data from the National Health and Nutritional Examination Survey (NHANES). Smoking status was categorized based on the recent tobacco use questionnaire. The receiver operating characteristic (ROC) curve analysis was performed to identify optimal cutoff concentrations by maximizing Youden's J index. The area under the curve (AUC) was used to compare 2CyEMA effectiveness with respect to serum cotinine. RESULTS: The overall cutoff concentration for the classification of cigarette smokers from nonsmokers was 7.32 ng/ml with high sensitivity and specificity (≥0.925). When stratified by demographic variables, the cutoff concentrations varied among subgroups based on age, sex, and race/Hispanic origin. Non-Hispanic Blacks had the highest cutoff concentration (15.3 ng/ml), and Hispanics had the lowest (4.63 ng/ml). Females had higher cutoff concentrations (8.80 ng/ml) compared to males (6.10 ng/ml). Among different age groups, the cutoff concentrations varied between 4.63 ng/ml (21-39 years old) and 10.6 ng/ml (for ≥60 years old). We also explored the creatinine adjusted cutoff values. CONCLUSIONS: 2CyEMA is an effective biomarker for distinguishing cigarette smokers from nonsmokers (users of noncombustible tobacco products or nonusers). IMPLICATIONS: Distinguishes smokers from noncombustible tobacco product users.

Exposure to 1,3-Butadiene in the U.S. Population: National Health and Nutrition Examination Survey 2011-2016.

1,3-Butadiene is a volatile organic compound with a gasoline-like odour that is primarily used as a monomer in the production of synthetic rubber. The International Agency for Research on Cancer has classified 1,3-butadiene as a human carcinogen. We assessed 1,3-butadiene exposure in the U.S. population by measuring its urinary metabolites N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (34HBMA), N-acetyl-S-(1-hydroxymethyl-2-propenyl)-L-cysteine (1HMPeMA), N-acetyl-S-(2-hydroxy-3-butenyl)-L-cysteine (2HBeMA), and N-acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine (4HBeMA). Urine samples from the 2011 to 2016 National Health and Nutrition Examination Survey were analysed for 1,3-butadiene metabolites using ultrahigh-performance liquid chromatography/tandem mass spectrometry. 34HBMA and 4HBeMA were detected in >96% of the samples; 1HMPeMA and 2HBeMA were detected in 0.66% and 9.84% of the samples, respectively. We used sample-weighted linear regression models to examine the influence of smoking status (using a combination of self-reporting and serum-cotinine data), demographic variables, and diet on biomarker levels. The median 4HBeMA among exclusive smokers (31.5 µg/g creatinine) was higher than in non-users (4.11 µg/g creatinine). Similarly, the median 34HBMA among exclusive smokers (391 µg/g creatinine) was higher than in non-users (296 µg/g creatinine). Furthermore, smoking 1-10, 11-20, and >20 cigarettes per day (CPD) was associated with 475%, 849%, and 1143% higher 4HBeMA (p < 0.0001), respectively. Additionally, smoking 1-10, 11-20, and >20 CPD was associated with 33%, 44%, and 102% higher 34HBMA (p < 0.0001). These results provide significant baseline data for 1,3-butadiene exposure in the U.S. population, and demonstrate that tobacco smoke is a major exposure source.

Characterization of the association between cigarette smoking intensity and urinary concentrations of 2-hydroxyethyl mercapturic acid among exclusive cigarette smokers in the National Health and Nutrition Examination Survey (NHANES) 2011-2016.

BACKGROUND: 2-Hydroxyethyl mercapturic acid (2HEMA, N-acetyl-S-(2-hydroxyethyl)-L-cysteine) is a urinary metabolite of several volatile organic compounds including acrylonitrile and ethylene oxide, which are found in cigarette smoke. METHODS: We measured 2HEMA concentrations in urine specimens collected during the National Health and Nutrition Examination Survey (2011-2016) from eligible participants aged >12 years (N = 7,416). We developed two multiple linear regression models to characterize the association between cigarette smoking and 2HEMA concentrations wherein the dependent variable was 2HEMA concentrations among participants who exclusively smoked cigarettes at the time of specimen collection and the independent variables included sex, age, race/ethnicity, creatinine, diet, and either cigarettes smoked per day (CPD) or serum cotinine. RESULTS: We detected 2HEMA in 85% of samples tested among exclusive cigarette smokers, and only 40% of specimens from non-smokers. When compared to exclusive cigarette smokers who smoked 1-9 CPD, smoking 10-19 CPD was associated with 36% higher 2HEMA (p < 0.0001) and smoking >19 CPD was associated with 61% higher 2HEMA (p < 0.0001). Additionally, 2HEMA was positively associated with serum cotinine. CONCLUSIONS: This study demonstrates that cigarette smoking intensity is associated with higher urinary 2HEMA concentrations and is likely a major source of acrylonitrile and/or ethylene oxide exposure.

Examination of xylene exposure in the U.S. Population through biomonitoring: NHANES 2005-2006, 2011-2016.

Aim: Xylenes are aromatic hydrocarbons used for industrial applications such as the production of petrochemicals and plastics. Acute xylene exposures can negatively impact health through neurotoxicity and irritation of respiratory and dermal tissues. We quantified urinary biomarkers of xylene exposure [2-methylhippuric acid (2MHA) and a mixture of 3- and 4-methylhippuric acids (34MH)] in a representative sample of the U.S. population. Methods: Spot urine obtained during the National Health and Nutrition Examination Survey 2005-2006 and 2011-2016 was analysed using ultra-high-performance liquid chromatography/tandem mass spectrometry. Exclusive smokers were distinguished from non-users using a combination of self-report and serum cotinine data. Results: The median 2MHA and 34MH levels were higher for exclusive smokers (100 µg/g and 748 µg/g creatinine, respectively) than for non-users (27.4 µg/g and 168 µg/g creatinine, respectively). Participants who smoked cigarettes had significantly higher 2MHA and 34MH levels (p < 0.0001) than unexposed participants. Smoking 1-10, 11-20, and >20 cigarettes per day (CPD) was significantly associated with 181%, 339% and 393% higher 2MHA levels, respectively. For 34MH, smoking 1-10, 11-20, and >20 CPD was significantly associated with 201%, 398%, and 471% higher 34MH levels, respectively. Conclusion: We confirm that tobacco smoke is a significant source of xylene exposure as measured by urinary 2MHA and 34MH levels.

Assessment of Serum Concentrations of 12 Aldehydes in the U.S. Population from the 2013-2014 National Health and Nutrition Examination Survey.

Aldehydes are known carcinogens and irritants that can negatively impact health. They are present in tobacco smoke, the environment, and food. The prevalence of aldehyde exposure and potential health impact warrants a population-wide study of serum aldehydes as exposure biomarkers. We analyzed 12 aldehydes in sera collected from 1843 participants aged 12 years or older in the 2013-2014 National Health and Nutrition Examination Survey. Several aldehydes were detected at high rates, such as isopentanaldehyde (99.2%) and propanaldehyde (88.3%). We used multiple linear regression models to examine the impact of tobacco smoke and dietary variables on serum concentrations of isopentanaldehyde and propanaldehyde. Although 12 serum aldehydes were analyzed and compared to tobacco smoke exposure, only isopentanaldehyde and propanaldehyde showed any significant association with tobacco smoke exposure. Survey participants who smoked 1-10 cigarettes per day (CPD) had 168% higher serum isopentanaldehyde and 28% higher propanaldehyde compared with nonusers. Study participants who smoked 11-20 CPD had higher serum isopentanaldehyde (323%) and propanaldehyde (70%). Similarly, study participants who smoked >20 CPD had 399% higher serum isopentanaldehyde and 110% higher serum propanaldehyde than nonexposed nonusers. The method could not, however, differentiate between nonexposed nonusers and nonusers exposed to secondhand smoke for either of these two aldehydes. No dietary variables were consistently predictive of serum isopentanaldehyde and propanaldehyde concentrations. This report defines baseline concentrations of serum aldehydes in the U.S. population and provides a foundation for future research into the potential health effects of aldehydes. In addition, this study suggests that tobacco smoke is a significant source of exposure to some aldehydes such as isopentanaldehyde and propanaldehyde.

Novel methods for the analysis of toxicants in bronchoalveolar lavage fluid samples from e-cigarette, or vaping, product use associated lung injury (EVALI) cases: Terpenes.

RATIONALE: Over 2800 e-cigarette, or vaping, product use-associated lung injury (EVALI) cases were reported to the Centers for Disease Control and Prevention (CDC) during August 2019 to February 2020. Bronchoalveolar lavage (BAL) fluid samples from 51 EVALI and 99 non-EVALI cases were analyzed for toxicants including terpenes. We describe a novel method to measure selected terpenes in BAL fluid by gas chromatography/tandem mass spectrometry (GC/MS/MS). METHODS: α-Pinene, ß-pinene, ß-myrcene, 3-carene, and limonene were measured in BAL fluid specimens by headspace solid-phase microextraction/gas chromatography/tandem mass spectrometry. We created and characterized BAL fluid pools from non-EVALI individuals to determine assay accuracy, precision, linearity, limits of detection, and analytical specificity. All measurements were conducted in accordance with the CDC's Division of Laboratory Sciences rigorous method validation procedures. RESULTS: Matrix validation experiments showed that calibration curves in BAL fluid and saline had similar slopes, with differences of less than 7%. The assay precision ranged from 2.52% to 5.30%. In addition, the limits of detection for the five analytes ranged from 1.80 to 16.8 ng/L, and the linearity was confirmed with R2 values >0.99. CONCLUSIONS: We developed and validated a method to quantify selected terpenes in BAL fluid specimens using GC/MS/MS. The assay provided accurate and precise analyses of EVALI and non-EVALI BAL fluid specimens in support of CDC's EVALI response. This method is applicable to the determination of a broad range of terpenes in BAL fluid specimens.

Novel methods for the analysis of toxicants in bronchoalveolar lavage fluid samples from e-cigarette, or vaping, product use-associated lung injury cases: Selected petroleum distillates.

RATIONALE: Over 2700 e-cigarette, or vaping, product use-associated lung injury (EVALI) cases were reported to the Centers for Disease Control and Prevention (CDC) during August 2019-February 2020. Bronchoalveolar lavage (BAL) fluid samples from 51 EVALI and 99 non-EVALI cases were analyzed for toxicants including petroleum distillates. We describe a novel method to measure petroleum distillates in BAL fluid using gas chromatography-mass spectrometry (GC/MS). METHODS: n-Hexane, n-heptane, n-octane, methylcyclopentane, and cyclohexane were measured in BAL fluid specimens by headspace solid-phase microextraction/GC/MS. We created and characterized BAL fluid pools from non-EVALI individuals to determine assay accuracy, precision, linearity, limits of detection (LODs), and analytical specificity. All measurements were conducted in accordance with the rigorous method validation procedures of CDC's Division of Laboratory Sciences. RESULTS: Matrix validation experiments showed that calibration curves in BAL fluid and saline had similar slopes, with differences less than 5%. Assay precision ranged from 1.98% to 18%. In addition, the LODs for the five analytes ranged from 0.05 to 0.10 µg/L, and their linearity was confirmed with R2 values >0.99. The analysis of selected petroleum distillates in BAL fluid analysis was shown to be comparable with their analysis in blood in which the 95th percentiles are below detection. CONCLUSIONS: We developed and validated a method to quantify petroleum distillates in BAL fluid specimens using GC/MS. The assay provided precise and accurate analyses of EVALI and non-EVALI BAL fluid specimens in support of CDC's EVALI response. This method is applicable to the determination of a broad range of volatile organic compounds in BAL fluid specimens.

Quantification of Seven Terpenes in Human Serum by Headspace Solid-Phase Microextraction-Gas Chromatography-Tandem Mass Spectrometry.

Terpenes are a class of volatile organic hydrocarbons commonly produced by vegetation and released into the atmosphere. These compounds are responsible for the scents of pine forests, citrus fruits, and some flowers. Human terpene exposure can come from inhalation, diet, smoking, and more recently, using e-cigarettes. Terpenes are present in tobacco smoke and are used as flavor chemicals in e-liquids. The health effects of terpenes are not widely known, though several studies have suggested that they may prove useful in future medical applications. We have developed a novel, high-throughput method of quantifying seven terpenes (α-pinene, ß-pinene, ß-myrcene, 3-carene, limonene, ß-caryophyllene, and α-humulene) in human serum to aid human-exposure investigations. This method employs headspace sampling using solid-phase microextraction (SPME) coupled to gas chromatography-tandem mass spectrometry to detect and quantify five monoterpenes and two sesquiterpenes in the low parts-per-trillion to low parts-per-billion range. The intraday and interday variability (percent error) of the method are ≤2 and ≤11%, respectively. In addition, this method showed excellent recovery in human serum (between 80 and 120% for all analytes). The assay precision ranges between 4.0 and 11%. Limits of detection ranged between 0.032 and 0.162 µg/L. Using serum cotinine values to classify tobacco use showed that smokers have higher serum concentrations of six terpenes compared to nonusers. Terpene concentrations were 14-78% higher in smokers than nonusers. Our method can provide essential biomonitoring data to establish baseline exposure levels for terpenes in humans.

Isoprene Exposure in the United States Based on Urinary IPM3: NHANES 2015-2016.

Isoprene is the 2-methyl analog of 1,3-butadiene and is a possible human carcinogen (IARC Group 2B). We assessed isoprene exposure in the general US population by measuring its urinary metabolite, N-acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-l-cysteine (IPM3) in participants (≥3 year old) from the 2015-2016 National Health and Nutrition Examination Survey. Spot urine samples were analyzed for IPM3 using ultrahigh-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Exclusive tobacco smokers were distinguished from non-users using a combination of self-reporting and serum cotinine data. IPM3 was detected in 80.2% of samples. The median IPM3 level was higher for exclusive cigarette smokers (39.8 µg/g creatinine) than for non-users (3.05 µg/g creatinine). Sample weighted regression analysis, controlling for creatinine, sex, age, race, body mass index, and diet, showed that IPM3 was positively and significantly associated with serum cotinine. Smoking 1-10 cigarettes per day (CPD, 0.5 pack) was significantly associated with an IPM3 increase of 596% (p < .0001), and smoking >20 CPD (>1 pack) was significantly associated with an IPM3 increase of 1640% (p < .0001), controlling for confounding variables. Drinking beer/ale at median and 90th percentile levels (compared to zero consumption) was associated (p < 0.05) with 0 and 2.9% increase in IPM3 in non-users, respectively. We conclude that tobacco smoke is a major source of isoprene exposure in the US population. This study provides important public health biomonitoring data on isoprene exposure in the general US population.

Factors Associated with Exposure to Trihalomethanes, NHANES 2001-2012.

Disinfection is critical for maintaining a safe water supply, but the use of chlorine or chloramine leads to exposure to disinfection byproducts (DBPs), including trihalomethanes (THMs), which have been associated with adverse reproductive outcomes and bladder cancer. The U.S. Environmental Protection Agency revised the DBP regulations starting in 1998 to further limit levels of THMs in household water. We analyzed data from the National Health and Nutrition Examination Survey (NHANES) collected between 2001 and 2012 (with 2 years per cycle) using models with and without water-related predictors to examine the utility of including these measures. Median blood chloroform levels (25th-75th percentiles) were 16.2 (9.13-31.2) ng/L in 2001-2002 and 5.97 (2.92-12.3) ng/L in 2011-2012. Median blood bromodichloromethane (BDCM) levels (25th-75th percentiles) were 2.22 (1.06-4.61) ng/L in 2001-2002 and 1.18 (

Evaluation of Bronchoalveolar Lavage Fluid from Patients in an Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injury - 10 States, August-October 2019.

CDC, the Food and Drug Administration (FDA), state and local health departments, and multiple public health and clinical partners are investigating a national outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI). Based on data collected as of October 15, 2019, 86% of 867 EVALI patients reported using tetrahydrocannabinol (THC)-containing products in the 3 months preceding symptom onset (1). Analyses of THC-containing product samples by FDA and state public health laboratories have identified potentially harmful constituents in these products, such as vitamin E acetate, medium chain triglyceride oil (MCT oil), and other lipids (2,3) (personal communication, D.T. Heitkemper, FDA Forensic Chemistry Center, November 2019). Vitamin E acetate, in particular, might be used as an additive in the production of e-cigarette, or vaping, products; it also can be used as a thickening agent in THC products (4). Inhalation of vitamin E acetate might impair lung function (5-7).

Nitromethane Exposure from Tobacco Smoke and Diet in the U.S. Population: NHANES, 2007-2012.

Nitromethane is a known toxicant and suspected human carcinogen. Exposure to nitromethane in a representative sample of the civilian, noninstitutionalized population in the United States ≥12 years old was assessed using 2007-2012 National Health and Nutritional Examination Survey (NHANES) data. Nitromethane was detected in all 8000 human blood samples collected, of which 6730 were used for analyses reported here. Sample-weighted median blood nitromethane was higher among exclusive combusted tobacco users (exclusive smokers; 774 ng/L) than nonusers of tobacco products (625 ng/L). In stratified sample-weighted regression analysis, smoking 0.5 pack of cigarettes per day was associated with a statistically significant increase in blood nitromethane by 150 ng/L, and secondhand smoke exposure (serum cotinine >0.05 ng/mL and <10 ng/mL) was statistically significant with a 31.1 ng/L increase in blood nitromethane. Certain dietary sources were associated with small but statistically significant increases in blood nitromethane. At median consumption levels, blood nitromethane was associated with an increase of 7.55 ng/L (meat/poultry), 9.32 ng/L (grain products), and 14.5 ng/L (vegetables). This is the first assessment of the magnitude and relative source apportionment of nitromethane exposure in the U.S. population.

Ethylbenzene and styrene exposure in the United States based on urinary mandelic acid and phenylglyoxylic acid: NHANES 2005-2006 and 2011-2012.

Ethylbenzene and styrene are air toxicants with widespread nonoccupational exposure sources, including tobacco smoke and diet. Ethylbenzene and styrene (EB/S) exposure was quantified from their common metabolites measured in spot urine samples obtained from participants (≥6 years old) in the 2005-2006 and 2011-2012 cycles of the National Health and Nutrition Examination Survey (NHANES; N = 4690). EB/S metabolites mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured using ultra-high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). MA and PGA were detected in 98.9% and 90.6% of tested urine specimens, respectively. Exclusive smokers had 2-fold and 1.6-fold higher median urinary MA and PGA, respectively, compared with non-users. Sampleweighted regression analysis among exclusive smokers showed that smoking 0.5 pack cigarettes per day significantly increased MA (+97.9 µg/L) and PGA (+69.3 µg/L), controlling for potential confounders. In comparison, exposure from the median daily dietary intake of grain products increased MA by 1.95 µg/L and was not associated with statistically significant changes in urinary PGA levels. Conversely, consuming vegetables and fruit was associated with decreased MA and PGA. These results confirm tobacco smoke as a major source of ethylbenzene and styrene exposure for the general U.S. population.

Initial Public Health Laboratory Response After Hurricane Maria - Puerto Rico, 2017.

Hurricane Maria made landfall in Puerto Rico on September 20, 2017, causing major damage to infrastructure and severely limiting access to potable water, electric power, transportation, and communications. Public services that were affected included operations of the Puerto Rico Department of Health (PRDOH), which provides critical laboratory testing and surveillance for diseases and other health hazards. PRDOH requested assistance from CDC for the restoration of laboratory infrastructure, surveillance capacity, and diagnostic testing for selected priority diseases, including influenza, rabies, leptospirosis, salmonellosis, and tuberculosis. PRDOH, CDC, and the Association of Public Health Laboratories (APHL) collaborated to conduct rapid needs assessments and, with assistance from the CDC Foundation, implement a temporary transport system for shipping samples from Puerto Rico to the continental United States for surveillance and diagnostic and confirmatory testing. This report describes the initial laboratory emergency response and engagement efforts among federal, state, and nongovernmental partners to reestablish public health laboratory services severely affected by Hurricane Maria. The implementation of a sample transport system allowed Puerto Rico to reinitiate priority infectious disease surveillance and laboratory testing for patient and public health interventions, while awaiting the rebuilding and reinstatement of PRDOH laboratory services.

Quantification of 19 Aldehydes in Human Serum by Headspace SPME/GC/High-Resolution Mass Spectrometry.

Sources of human aldehyde exposure include food additives, combustion of organic matter (tobacco smoke), water disinfection byproducts via ozonation, and endogenous processes. Aldehydes are potentially carcinogenic and mutagenic, and chronic human aldehyde exposure has raised concerns about potential deleterious health effects. To aid investigations of human aldehyde exposure, we developed a novel method to measure 19 aldehydes released from Schiff base protein adducts in serum using controlled acid hydrolysis, solid-phase microextraction (SPME), gas chromatography (GC), and high-resolution mass spectrometry (HRMS). Aldehydes are released from Schiff base protein adducts through acid hydrolysis, and are quantified in trace amounts (µg/L) using stable isotope dilution. Detection limits range from 0.1 to 50 µg/L, with calibration curves spanning 3 orders of magnitude. The analysis of fortified quality control material over a three-month period showed excellent precision and long-term stability (3-22% CV) for samples stored at -70 °C. The intraday precision is also excellent (CV, 1-10%). The method accuracy ranges from 89 to 108% for all measured aldehydes, except acrolein and crotonaldehyde, two aldehydes present in tobacco smoke; their analysis by this method is not considered robust due in part to their reactivity in vivo. However, results strongly suggest that propanal, butanal, isobutanal, and isopentanal levels in smokers are higher than levels in nonsmokers, and thus may be useful as biomarkers of tobacco smoke exposure. This method will facilitate large epidemiological studies involving aldehyde biomonitoring to examine nonoccupational environmental exposures.

Crotonaldehyde exposure in U.S. tobacco smokers and nonsmokers: NHANES 2005-2006 and 2011-2012.

INTRODUCTION: Crotonaldehyde is an α,ß-unsaturated carbonyl compound that is a potent eye, respiratory, and skin irritant. Crotonaldehyde is a major constituent of tobacco smoke and its exposure can be quantified using its urinary metabolite N-acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (HPMM). A large-scale biomonitoring study is needed to determine HPMM levels, as a measure of crotonaldehyde exposure, in the general U.S. MATERIALS AND METHODS: Urine samples were obtained as part of the National Health and Nutrition Examination Survey 2005-2006 and 2011-2012 from participants who were at least six-years-old (N = 4692). Samples were analyzed for HPMM using ultra performance liquid chromatography - tandem mass spectrometry. Exclusive tobacco smokers were distinguished from non- tobacco users through a combination of self-reporting and serum cotinine data. RESULTS: Detection rate of HPMM among eligible samples was 99.9%. Sample-weighted, median urinary HPMM levels for smokers and non-users were 1.61 and 0.313 mg/g creatinine, respectively. Multivariable regression analysis among smokers showed that HPMM was positively associated with serum cotinine, after controlling for survey year, urinary creatinine, age, sex, race, poverty level, body mass index, pre-exam fasting time, and food intake. Other significant predictors of urinary HPMM include sex (female > male), age (children > non-user adults), race (non-Hispanic Blacks < non-Hispanic Whites). CONCLUSIONS: This study characterizes U.S. population exposure to crotonaldehyde and confirms that tobacco smoke is a major exposure source. Urinary HPMM levels were significantly higher among exclusive combusted tobacco users compared to non-users, and serum cotinine and cigarettes per day were significant predictors of increased urinary HPMM. This study also found that sex, age, ethnicity, pre-exam fasting time, and fruit consumption are related to urinary HPMM levels.

Succinylacetone as primary marker to detect tyrosinemia type I in newborns and its measurement by newborn screening programs.

Tyrosinemia type I (TYR I) is caused by autosomal recessive fumarylacetoacetate hydrolase deficiency and is characterized by development of severe liver disease in infancy and neurologic crises. If left untreated, most patients die of liver failure in the first years of life. Intervention with medication is effective when initiated during the first month of life. This improvement in the treatment of TYR I patients influenced the decision to include TYR I in the US Secretary of the Department of Health and Human Services' (HHS) Recommended Uniform Screening Panel. However, while tyrosine is routinely measured in newborn screening (NBS) by tandem mass spectrometry (MS/MS), elevated tyrosine levels are not specific to TYR I. To improve the specificity of NBS for TYR I, several assays were developed to measure succinylacetone (SUAC) in dried blood spots (DBS). SUAC is a pathognomonic marker of TYR I, and its detection by NBS MS/MS is possible. This review of the current status of NBS for TYR I in the US is the result of discussions at the HHS Secretary's (Discretionary) Advisory Committee on Heritable Disorders in Newborns and Children about the inconsistent implementation of effective NBS for TYR I in the US. We sought to understand the different TYR I screening practices in US NBS programs. Results indicate that 50 out of 51 NBS programs in the US screen for TYR I, and a successful SUAC performance evaluation scheme is available from the Centers for Disease Control and Prevention. Programmatic and methodological barriers were identified that prevent widespread adoption of SUAC measurements in NBS laboratories. However, since SUAC detection is currently the best approach to NBS for TYR I, a further delay of the addition of SUAC measurement into NBS procedures is discouraged. SUAC measurement should improve both the false positive and false negative rate in NBS for TYR I thereby yielding the desired benefits for affected patients at no expense to the overall population served.

Neonatal screening for lysosomal storage disorders: feasibility and incidence from a nationwide study in Austria.

BACKGROUND: The interest in neonatal screening for lysosomal storage disorders has increased substantially because of newly developed enzyme replacement therapies, the need for early diagnosis, and technical advances. We tested for Gaucher's disease, Pompe's disease, Fabry's disease, and Niemann-Pick disease types A and B in an anonymous prospective nationwide screening study that included genetic mutation analysis to assess the practicality and appropriateness of including these disorders in neonatal screening panels. METHODS: Specimens from dried blood spots of 34,736 newborn babies were collected consecutively from January, 2010 to July, 2010, as part of the national routine Austrian newborn screening programme. Anonymised samples were analysed for enzyme activities of acid ß-glucocerebrosidase, α-galactosidase, α-glucosidase, and acid sphingomyelinase by electrospray ionisation tandem mass spectrometry. Genetic mutation analyses were done in samples with suspected enzyme deficiency. FINDINGS: All 34,736 samples were analysed successfully by the multiplex screening assay. Low enzyme activities were detected in 38 babies. Mutation analysis confirmed lysosomal storage disorders in 15 of them. The most frequent mutations were found for Fabry's disease (1 per 3859 births), followed by Pompe's disease (1 per 8684), and Gaucher's disease (1 per 17,368). The positive predictive values were 32% (95% CI 16-52), 80% (28-99), and 50% (7-93), respectively. Mutational analysis detected predominantly missense mutations associated with a late-onset phenotype. INTERPRETATION: The combined overall proportion of infants carrying a mutation for lysosomal storage disorders was higher than expected. Neonatal screening for lysosomal storage disorders is likely to raise challenges for primary health-care providers. Furthermore, the high frequency of late-onset mutations makes lysosomal storage disorders a broad health problem beyond childhood. FUNDING: Austrian Ministry of Health, Family, and Women.